Vacuum feeding apparatus



United States Patent [72] inventor Stanley William Middleditch PottersBar, England [21] Appl. No. 815,847 [22] Filed April 14, 1969 [45]Patented Nov. 24, 1970 [73] Assignee De La Rue Instruments LimitedLondon, England a corporation [32] Priority April 26, 1968 [33] GreatBritain [31] No. 19,862/68 [54] VACUUM FEEDING APPARATUS 8 Claims, 1Drawing Fig.

52 U.S.Cl 221/211, 221/9; 214/8.5 [51] Int. Cl ..'B65g 59/04; B65h 3/08[50] Field ofSearch 221/21 1, 9, 10,225, 221, 236;214/8.5

[56] References Cited UNITED STATES PATENTS 3,045,867 7/1962 Flynn221/211 3,063,578 11/1962 Millar 22l/2l1X 3,456,816 7/1969 GallowayPrimary Examiner-David M. Bockenck Attorney-Baldwin, Wight & BrownABSTRACT: Apparatus for dispensing articles one at a time from a stackof such articles, characterised in that it comprises the combination ofa. stack support means.

b. a suction gripper in a datum position for transferring said articlesone by one to an unloading station,

c. means for advancing said stack support means towards said suctiongripper for loading said gripper with the foremost article of saidstack.

d. means adapted cyclically to reciprocate said suction gripper betweensaid datum position and said unloading station after loading saidsuction gripper.

e. suction-sensitive means operable on loading of said suction gripperfor arresting operation of said advancing means. and

f. control means for preventing reactuation of said advancing meansuntil the suction gripper is returned to the datum position at the endolthe cycle.

VACUUM FEEDING APPARATUS This invention relates to apparatus fordispensing articles one at a time from a stack of such articles.

In particular this invention relates to sheet or article feedingapparatus of the type comprising a vertical stack or pile ofhorizontally disposed sheets or articles, an oscillatory suction liftingmeans connected to a source of vacuum adapted to remove sheets orarticles singly from the top of the pile and transport them to adelivery stage and a pile elevator capable of maintaining the uppersurface of the pile at a substantially constant position.

The invention is specifically intended for use in the feeding of bandedassemblies of sheets, for example packets of banknotes, into thedelivery stage of an automatic voucheroperated or card-operated cashdispensing machine. However, it may advantageously be applied to otheranalagous apparatus wherein it is desired to feed or dispense singlesheets or articles into a delivery or receiving means in a reliablemanner.

In the case of handling packets or assemblies of sheets considerabledifficulties are experienced in maintaining the upper surface of thepile at a desired constant height withrespect to the suction liftingmeans because of the inherent inconsistent resilience or spring ofthepackets within the pile. For example packets of banknotes may includeeither/or both new and used notes and the tightness of the banding andthe degree of wear or edge distortion of the notes will inevitablycreate a compressible assembly of indeterminate thickness. Ac cordingly,a free-pile height of approximately 20 inches may possess acompressibility in the order of 2 inches of vertical displacement.

On the one hand it is essential that the pile is sufficiently high toenable it to be acted upon by the suction lifting means in a positiveand reliable manner before the commencement of the oscillatory movementof the lifting means and on the other hand it must notbe raised too orotherwise impede the return movement of the suction lifting means.

We have found that pile height sensing devices of the type well known inthe printing industry are not capable of controlling the pile elevatingmeans in accordance with the above requirements. For example, aconventional sensing arm adapted to bear upon the top of a pile isunable to sense accurately the free height of the pile because of theaforementioned inconsistent resiliency and, secondly, because theexistence of the arm restricts vertical movement of the topmost packetwhilst it is being acted upon by the suction lifting arm.

lt is also well known to employ an oscillatory suctionoperated devicewhich is capable of ascending and descending upon the top of a pile andwhich is adapted to initiate operation of the pile elevating mechanismwhen it descends below a predetermined limit. This device may comprise aheight detector which is arranged to oscillate in unison with aconventional suction sheet removal means, or alternatively it maycomprise a single component of telescopic construction which is capableof performing the combined function of detecting and sheet lifting. Eachof these known devices is satisfactory when used in conjunction withrelatively nonresilient piles, such as virgin sheets of paper of thetype encountered in the printing industry, but is incapable of actingsatisfactorily upon resilient piles.

The present invention provides apparatus for dispensing articles one ata time from a stack of such articles, comprising:

a. stack support means,

b. a suction gripper in a datum position for transferring said articlesone by one to an unloading station,

c. means for advancing said stack support means towards said suctiongripper for loading said gripper with the foremost articles of saidstack,

d. means adapted cyclically to reciprocate said suction gripper betweensaid datum position and said unloading station after loading saidsuction gripper, Y

e. suction-sensitive means operable on loading of said suction gripperfor arresting operation of said advancing means, and

high thereby to obstruct v f. control means for preventing reactuationof said advancing means until the suction gripper is returned to thedatum position at the end of the cycle.

The apparatus may include means for breaking the suction when saidsuction gripper is in the unloading station, although the article may,for example, be mechanically removed from the gripper.

In one embodiment of the invention the suction gripper comprises a pairof downwardly directed suction cups, and said advancing means isarranged to lift said stack support means upwardly towards said cups,the suction cups being supported for sideways and upward movement fromsaid datum position to said unloading station by a pair of slewing armseach pivoted about a horizontal axis to a substantially verticalangularly rotatable spindle.

One of said spindles may be angularly rotated by a reciprocableconnecting rod pivotally connected at one end by a link to said spindleand pivotally connected at its other end to a rotatable cam disc, drivemeans being provided for rotating said cam disc through one revolutionto effect cyclic movement of said suction gripper.

The cam disc may include a projection arranged to engage and pivot alever, when the gripper is in the unloading position, to expose a portin a suction conduit for said suction gripper thereby to break thesuction and release the article.

The advancing means preferably comprises an electric motor in anelectrical circuit including a pressure-sensitive switch, constitutingthe suction-sensitive control means, in communication with said suctiongripper and adapted to open on loading of said gripper, an electricalswitch, constituting said second control means, being included in saidcircuit to coact with one of said slewing arms and arranged to openduring the cyclic movement ofthe suction gripper.

A nonlimiting example of the invention will now be described withreference to the accompanying drawing which is a diagrammaticperspective view of the essential components of the article-dispensingapparatus. it will be appreciated that for reasons of clarity allstructural framework and noncritical mechanical and electricalcomponents have been omitted from the drawing.

A stack or pile l of banded packets la of banknotes is stackedvertically upon a horizontal pile support plate 2 which is capable ofbeing elevated by a geared electric motor 3 by means of a sprocket andchain system shown diagrammatically at 4. The arrangement is such thatenergisation of the motor will cause the support plate and the packetsdisposed thereon to rise slowly.

Additionally a clutch (not shown) is incorporated in the transmissionsystem to enable the support plate 1 to be operated manually for thepurpose of servicing the apparatus or replenishing the supply pile. Asuitable guiding means (not shown) is also provided externally of thepile of to maintain the packets in vertical alinement The suctionlifting means comprises a suction gripper constituted by a pair ofspaced downwardly-directed nonresilient suction cups 5 which areattached to a hollow beam 6 integral with a hollow transverse bar member7. The extremities of the bar member are pivotally attached to a pair ofparallel slewing arms 8 and 9, the opposite ends of which are pivotallymounted in the forked ends of two vertical shafts l0 and 11. Thedistance between the shafts l0 and 11 is identical to that of theeffective length of the bar member 7, so that the latter member and thetwo arms 8 and 9 comprise a parallelogram linkage system. The arms 8 and9 are free to pivot vertically within the fork ends by means ofhorizontal pin joints l2 and 13.

A linear cam plate 14 is fixedly attached to the framework of theapparatus and is provided with an upper cam surface 14a capable ofcoacting with the underside of the arm 8. The suction lifting assemblyas referred to above is oscillated in an arcuate manner about thevertical shafts l0 and 11 by means of a crank disc 15 and a lever 16fast with the shaft 10, the lever 16 and crank disc being connected by aconnecting rod 17 pivoted thereto at its ends. The crank disc is drivenin a unidirectional manner by means of a geared electric motor 18, theelectrical energisationof which is broken by means (not shown) everywhole revolution of the'disc thus to position the suction cups 5 abovethe pile 1 in the manner illustrated at the end ofa cycle. I

An inclined delivery chute 19 is attached to the framework of theapparatus and-is positioned immediately below the suction cups when theyare in their extreme limit ofmovement, as indicated by the chain-dottedlines.

An upstanding brush 20 is provided adjacent to the side edge of the topof the pile 1 to strip off any packet which may have inadvertentlyadhered to the underside of the packet being acted upon by the liftingmeans.

The pneumatic system comprises an internal passageway formed within thebeam 6 which terminates at the interior of the suction cups and extendsvertically through the centre of the transverse member 7 to a connectionpipe 21. The pipe 21 receives one end of a flexible tube 22 the oppositeend of which is mounted upon a hollow cruciform junction member 23 in afluid-tight manner. The upper vertical limb of the member 23 is providedwith a pressure sensitive electrical switch S, and the side limbs 24 and25 connect, respectively,

to a source of vacuum V, and an air inlet valve 26. The switch S, isprovided with a pair of normally closed contacts which serve to break anelectrical circuit for the elevating motor 3 when a predetermined degreeof suction exists within the system.

The air inlet valve 26 comprises a resilient pad 26a mounted upon alever 27 pivoted at 27a. The pad 26a is spring-loaded against the end ofthe hollow limb 25 thereby to seal same from atmospheric pressure. Theopposite end of the lever 27 is capable of being deflected (as indicatedby a'chain-dotted line) by a projection 28 attached to the periphery ofthe crank disc 15. Thus. when the disc is rotated to position thesuction cups 5 above the chute 19 the air inlet valve 26 will open andadmit atmospheric air into the system thus temporarily breaking thevacuum.

A second electrical switch S is provided for the purpose of immobilisingthe pile elevating means when the suction cups 5 are not situated intheir'rest positions. i.e. above the pile 1. This switch is situatedadjacent the cam' plate 14 and its operating blade is actuated by theunderside of the arm 8. It thus closes the contacts only whilst theapparatus is in the position as illustrated.

The electric circuit to the pile elevating motor 3 comprises valve 26will be opened to atmosphere thus breaking the of suction will notrestart the pile elevating motor 3 because the circuit is broken by theswitch 8:. It will further be realized that the oscillatory movement ofthe lifting means will cause the lever 8 to coact with the stationarycam surface 14 thereby to raise the suction cups. together with thepacket adhered thereto, from the remainder of the pile. The return ofthe lifting means will follow an identical path and it therefore followsthat the suction cups will descend over the pile and the possibility ofobstructing or fouling the pile is eliminated.

The feeding means is thereafter positioned in readiness for thefollowing feeding cycle which will again cause the pile to elevate ifnecessary.

Whilst a delivery chute is specifically referred to in the Idescription, any suitable alternative delivery arrangement may beemployed. For example, the packet may be deposited into a slideable trayor fedinto the nip of a roller system.

The apparatus described above has a fail-safe feature in that if thevacuum pipes become disconnected or a hole formed therein so thatthestack continues to rise after loading the gripper, the spring blade ofswitch S: will open thus stopping motor 3.

lclaim:

1. Apparatus for dispensing articles one at a time from a stack of sucharticles, characterised in that it comprises the the two switches S, andS wired in series configuration with a source of electricity. In actualpractice this electrical circuit is only live whilst the apparatusassociated withv the above described feeding means is in operation.

The operation of the feeding means is instigated from a stand-by or"prepare" input signal derived for example from the aforementionedassociated cash-dispensing apparatus, which energises an electricalcircuit to drive a vacuum pump thereby to create vacuum within thejunction member 23 and energise the circuit for motor 3. Assuming thatthe top of the pile l is below the level of the underside of the suctioncups 5 air will enter between same and the top of the pile accordinglythe contacts of the switch S, will remain closed because there will beno buildup of suction within the system. The effect of this is, toenergise the pile elevating motor 3 which serves to raise the pile 1.When the topmost packet in the pile contacts both of the suction cupssuction will be created in the system and the contacts of thepressure-sensitive switch S, will open to break the circuit to theelevating motor 3. The apparatus is thus immediately ready for receivingan acceptance input signal from the apparatus above which energises themotor 18 which, through the medium of the crank disc 15, the connectingrod 17 and the lever 16 fast with the vertical shaft 10, oscillates thesuction lifting means to the position, indicated by the chain-dottedline, above the delivery chute 19. At the end of this movement the airinlet combination of:

a. stack support means;

b. a suction gripper in a datum position for transferring said articlesone by one to an unloading station;

c. means for advancing said stack support means towards said suctiongripper for loading said gripper with the foremost article of saidstack;

cl. means adapted cyclically to reciprocate said suction gripper betweensaid datum position and said unloading station after loading saidsuction gripper;

e. suction-sensitive means operable on loading of said suction gripperfor arresting operation of said advancing .means; and

f. control means for preventing reactuation of said advancing meansuntil the suction gripper is returned to the datum position at the endof the cycle.

2. Apparatus according to claim 1 characterised in that theadvancingmeans comprises a geared electric motor and thesuction-sensitive means comprises a suction-sensitive electrical switchin an electrical circuit with said motor and in pneumatic communicationwith the suction gripper.

3. Apparatus according to claim 2 characterised in that the controlmeans comprises an electrical switch in said electrical circuit.

4. Apparatus according to claim 3 characterised in that the suctiongripper is attached to an arm adapted for movement in such a-manner thateach article is lifted from the top of the stack and transported to theunloading station.

5. Apparatus according to claim 4 characterised in that the suctiongripper is pivotally mounted to the extremities of a pair of parallelarms the opposite ends of which are pivotally attached to the frameworkof theapparatus.

6. Apparatus according to claim 5 characterised in that it furtherincludes a fixedly mounted cam plate adapted to engage with one of thearms and a geared electric motor adapted to reciprocate said arm alongthe cam plate away from and towards said datum position via saidunloading station.

7. Apparatus according to claim 4 characterised in that means areprovided to admit atmospheric air into the suction gripper when it is atsaid unloading station.

8. Apparatus according to claim 1 characterised in that the suctiongripper comprises at least one downwardly directed nonresilient suctioncup.

